Brown Institute for Brain Science

Modified Barnes Maze Test

Rationale of Test

The modified Barnes maze can be used as a land-based analog for the Morris water maze task. This task similarly indexes an animals spatial learning abilities and can be used to assess hippocampus-dependent memory functioning.

Apparatus

The testing apparatus is a circular platform with numerous 2” diameter “escape holes” (20) ringed around the periphery of the platform. Only one of the escape holes is connected to an escape box, allowing the mouse to leave the platform. The platform is place in a brightly lit room to create an aversive environment to encourage the mice to seek out the target escape hole. Visual cues attached to the walls of the room surrounding the maze provide spatial orienting cues. The arena is set up under a digital camera connected to a computer equipped with a digitizer board and digital tracking software.

Procedure

The subject is placed in the center of the platform at the start of each trial and given a defined period of time (5-10min) to find the escape hole. Animals that fail to enter the escape hole in time are led to it by the experimenter and allowed to briefly remain in the escape hatch before being returned to their home cage. Animals are given 1-2 trials per day, and testing typically is repeated over the course of 5 days. The location of the escape hole remains the same across trials and changes in distance of the path to and latency to find the escape hole are recorded. On the final day(s) of testing the location of the escape hole can be changed, and the time it takes to remap the location of the escape hatch can be calculated.

Interpretation

Differences in the duration and path to the escape hole over the course of repeated trials can be used as an indicator of hippocampus-dependent memory function. Amount of time to remap the new location of the escape platform can be used as a measure of cognitive flexibility.

Relevant Controls

Care should be taken to insure no impairments in sensory function, motor function, or anxiety-like behavior.